1) Field of the Invention
The present invention relates to a method for making a can such as a paint can, to an apparatus for making a can and to such can and can body.
2) Prior Art
Cans such as paint can, are generally provided with ring which is adhered to the can body such as by seaming, welding or gluing. This ring has an opening with a diameter which is selected such that a lid for such can will be accommodated in the ring opening with a well defined clamping force. This clamping force is selected such that under normal handling conditions the lid will stay on the can and the can content not spoiled. At the same time the clamping force is such that the user is able to remove the lid from the can without application of excessive force and without damaging the can, particularly when a tool such as a screw driver, is used for removing the lid. These characteristics for the lid generally require that the ring is made in a separate process and apparatus such that the delicate form and shape can be maintained and controlled independently from the process and apparatus for making the can body. Ultimately, the separate ring is adhered to the can body thereby forming the can.
Obviously, the separate production of such rings from a sheet of metal results in a relatively large amount of spoiled material formed when cutting out the central area thereby forming the ring opening. In addition, an additional operational step is required for adhering the ring to the can body.
When under circumstances the clamping of the lid on the can body by the ring cannot be guaranteed then an separate clamping band or strip is to applied to the upper area of the can in order to generate additional clamping force. The use of such clamping band or strip is costs increasing and after its removal the clamping force is no longer optimal.
The present invention has for its object to provide a can which substantially overcomes the above mentioned drawbacks and still a lid can be applied to the can body and maintained with adequate clamping force without the need of a separate adhered ring and/or clamping band or strip. At the same time the lid can be removed by the user in the usual manner without exerting excessive force.